Well, honestly, it makes my life a lot easier to have my old iPad docked on the 1608 and my new iPad running off WiFi. If Mackie decides to discontinue support for MF4.xx, then so be it. I will either buy a new mixer at that point or hope that Mackie will allow docking with some kind of an upgraded hardware addition to the DL1608. I am not sure how much longer my old iPad 3 will even last or when it will die, but I can see myself upgrading to a newer iPad again in a couple of years. But without the ability to dock the DL1608 does lose some of its attractiveness to me.
Then again, the mixer has served me well for over 8 years, so if I have to buy another mixer if support for MF4 is discontinued and I still want to use both iPads, then it is what it is. I do like the Presonus StudioLive mixers, and though I am not a fan of Behringer, their X32 has gotten rave reviews from a lot of my sound man friends. I suppose the Mackie DL32s and DL32r are also worth a look if that happens.